1. Field of the Invention
This invention relates to improvements in watercraft of the catamaran type. More particularly, it relates to a catamaran having a third hull.
2. Description of the Prior Art
Catamarans are twin-hulled boats that may be propelled by the wind, by motors, or both; the hulls are laterally spaced apart from one another and are connected by a deck means. The deck may be a rigid, structural part of the craft, or it may be a framework covered by a suitable fabric. In some boats or ships, the deck may be a combination of fabric and rigid materials.
The invention disclosed hereinafter relates primarily to improvements in the design of catamarans having rigid, structural decks, but it also has utility in connection with catamarans having nonstructural decks as well.
There are two problems that are inherent in catamaran design. The first problem relates to the pounding that the underside of the deck takes in high seas and the concomitant unpleasant effect such pounding has on the passengers, both as to noise and impact. A very large catamaran is less subject to this problem because the underside of its deck is high above the waves. Thus, there is a need for a design that alleviates this problem in all but the largest catamarans. The second problem relates to the tendency of the bow of all but the largest catamarans to become submerged either as a result of high seas or as a result of strong winds, i.e., a sailing catamaran bow may become submerged even in calm water from the force of the sail if the wind is strong. A submerged bow results in loss of control and possible capsize. Accordingly, there is a need for a catamaran design that would prevent bow submersion or, at least, provide quick recovery in the event high seas or strong winds cause such bow submersion.
Earlier inventors have added a third hull to catamarans in an attempt to alleviate both of these problems. However, the known three hull designs include a third hull that is submerged only when encountering waves, i.e., such third hulls are not submerged in calm water. Such third hulls attenuate the force of the waves pounding on the underside of the deck at least to some extent and they add buoyancy to the bow, but they do not solve these problems entirely.
U.S. patents showing multiple hull boats include Design U.S. Pat. No. 191,020 to Fry and utility U.S. Pat. No. 3,345,967 to Sweet. U.S. patents disclosing extra keels include U.S. Pat. Nos. 3,773,006 to Black, 3,469,549 to Rae, 3,902,445 to Stolk, and 1,620,349 to Hickman.
Still further U.S. patents of interest include U.S. Pat. Nos. 2,735,392, 4,890,564, Des. U.S. Pat. Nos. 236,145, 4,903,626, 911,806, 4,091,761, 4,924,797, 3,702,598, 4,233,920, and 4,932,347.
Foreign patents of interest include United Kingdom Nos. 471,741, 1,407,426, 1,541,639, and France Nos. 2,571,330, 1,025,312, and 2,636,295.
Although these designs represent improvements over conventional, twin-hulled catamarans, they still have shortcomings. For example, some of them include third hulls that extend the entire length of the watercraft; obviously, this adds a considerable amount of manufacturing expense. Perhaps more importantly, such full-length third hulls change the performance characteristics of the watercraft so much that the craft is no longer recognizable as a catamaran.
Still other designs incorporate third hulls that extend from the bow of the boat to a point about mid-length thereof and which are submerged only momentarily when encountering waves. These hulls are provided to assist in the planing of the craft over the water. These craft are known as planing boats because they skim over the surface of the water.
Thus, none of the known designs include fully submerged third hulls that extend less than the full length of the craft.
What is needed, then, is a three hull design that provides the buoyancy of a three hull craft without detracting from the performance of the craft. The ideal design would also vitiate the pounding of the waves on the underside of the deck, even though the ideal third hull would not extend the entire length of the craft. However, at the time the present invention was made, the prior art, when considered as a whole as required by law, neither taught nor suggested to those of ordinary skill in the boat building industry how the ideal design could be achieved.